1. Field of the Invention
The present invention relates to a semiconductor component.
2. Description of the Prior Art
Recently, home electric appliances and information devices have been made smaller in size in quick tempo up to the degree which permits the users to carry them. One of the factors which have promoted such reduction in size of home electric appliances and information devices is a single chip microcomputer. The single chip microcomputer comprises a central processing unit (hereinafter referred to as "CPU"), memories such as ROM and RAM, and such functional circuits as timers, all of which are formed on a single semiconductor chip. The use of the single chip microcomputer has promoted the reduction in size of a mounting substrate and of home electric appliances and information devices.
However, for small-sized devices requiring large capacities of memories, which have recently been developed positively, there is adopted a method in which a CPU and a memory of a large capacity are mounted on separate semiconductor chips, then the semiconductor chip ("CPU chip" hereinafter) provided with the CPU is packaged into a microcomputer module, likewise the semiconductor chip ("memory chip" hereinafter) provided with the large-capacity memory is packaged into a large-capacity memory module ("memory module" hereinafter), then the microcomputer module and the memory module are mounted onto a mounting substrate, and both modules are connected with each other through wiring formed on the upper surface of the mounting substrate. This is because as the memory capacity increases, the area occupied by memory becomes larger and it becomes impossible to provide both large-capacity memory and CPU on one semiconductor chip.
FIG. 16 is a perspective view showing the construction of a conventional IC module, in which are illustrated both microcomputer module and memory module. In the same figure, the reference numeral 121 denotes a microcomputer module and the numeral 131 denotes a memory module. The microcomputer module 121 plays the role of controlling a small-sized device, while the memory module 131 plays the role of storing data necessary for the control of the small-sized device made by the microcomputer module 121.
Numeral 122 denotes the body of the microcomputer module. Numeral 123 denotes a first outer lead for connection between the modules, the first outer lead 123 being provided plurally on the microcomputer module body 122 and drawn out to the exterior from a side face of the body 122 up to a position flush with the underside of the body 122. Numeral 124 denotes a second outer lead provided plurally on the microcomputer module body 122 and drawn out to the exterior from side faces of the body 122 up to positions flush with the underside of the body 122. The first outer leads 123 permit the microcomputer module 121 to receive data from the memory module 131 and permit the microcomputer module 121 to transmit a control signal to the memory module 131 for controlling the operation of the module 131. The second outer leads 124 permit the microcomputer module 121 to be supplied with electric power and permit the same module to receive and transmit information signals from and to the exterior of the small-sized device.
Numeral 132 denotes the body of the memory module. Numeral 133 denotes a first outer lead for connection between both modules, the first outer lead 133 being provided plurally on the memory module body 132 and drawn out to the exterior from a side face of the body 132 up to a position flush with the underside of the body 132. Numeral 134 denotes a second outer lead provided plurally on the memory module body 132 and drawn out to the exterior from side faces of the body 132 up to positions flush with the underside of the body 132. The first outer leads 133 permit the memory module 131 to receive a control signal from the microcomputer module 121 and transmit data to the module 121. The second outer leads 134 permit the memory module 131 to be supplied with electric power and permit the same module to receive an information signal from the exterior of the small-sized device.
The CPU chip sealed in the microcomputer module body 122 and the first and second outer leads 123, 124 are electrically connected with each other. Likewise, the memory chip sealed in the memory module body 132 and the first and second outer leads 133, 134 are electrically connected with each other.
FIG. 17 is a perspective view showing the construction of a conventional semiconductor component. The semiconductor component shown therein comprises the microcomputer module and the memory module both illustrated in FIG. 16 and both mounted on a mounting substrate. The numeral 141 in FIG. 17 represents the semiconductor component.
Numeral 142 denotes a mounting substrate. Numeral 143 denotes a connecting wire formed on the upper surface of the mounting substrate 142. The connecting wire 143 connects the portion where the first outer leads 123 of the microcomputer module 121 contacts the upper surface of the mounting substrate 142 with the portion where the first outer leads 133 of the memory module 131 opposed thereto contacts the upper surface of the substrate 142. The other constituent elements are the same as those indicated by the same reference numerals in FIG. 16, so detailed explanations thereof are here omitted.
The conventional semiconductor component 141 illustrated in FIG. 17 is constructed as follows. The microcomputer module 121 and the memory module 131 are mounted on the substrate 142 at the shortest distance between both modules. Then, the portion where the first outer leads 123 of the microcomputer module 121 contacts the upper surface of the substrate 142 and the portion where the outer leads 133 of the memory module 131 opposed thereto contact the upper surface of the substrate 142 are connected with each other by using the connecting wires 143 formed on the upper surface of the substrate 142.
Reference will be made below to the operation of such conventional semiconductor component.
Main operations are as follows. The microcomputer module 121 transmits a control signal for controlling the operation of the memory module 131 to the memory module through the first outer leads 133. The memory module 131 receives the control signal through the first outer leads 133. In accordance with this control signal the memory module 121 operates and transmits data to the microcomputer module 121 through the first outer leads 133, which data is necessary for the microcomputer module 121 to control the small-sized device. The microcomputer module 121 receives the data through the first outer leads 123. In accordance with this data the microcomputer module 121 controls the small-sized device and transmits an information signal to the exterior of the device through the second outer leads 124.